INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 7, No 1, 2016 © Copyright by the authors - Licensee IPA- Under Creative Commons license 3.0 Research article ISSN 0976 – 4402 Received on May 2016 Published on July 2016 1 Heavy metal removal through bacterial biomass isolated from various contaminated sites Isha Vishan 1 , Ajay S. Kalamdhad 2 1 Centre for the Environment, Indian Institute of Technology Guwahati (IITG), Guwahati 781039, Assam, India 2 Department of Civil Engineering, Indian Institute of Technology Guwahati (IITG), Guwahati 781039, Assam, India reachisha01@gmail.com doi: 10.6088/ijes.7001 ABSTRACT Heavy metal contamination causes serious threat to the ecosystem. Microbe metal interaction has been most sought after topic in terms of the usage of microbes in removing heavy metals from the surrounding environment along with the bioremediation. It is the most efficient and least costly method for treating heavy metal contaminated areas. Varied number of bacteria, fungi, algae and yeasts had been reported for removing heavy metals effectively. Industrial waste, wastewater, soils, plant roots and compost have been found to be good sources of heavy metal resistant microbes. Biosorption technology applies to the inanimate biosorbents as well as to living and non-living microorganisms. Therefore, this review paper highlights the microbiological aspect of heavy metal removal in the wastewater, industrial effluents, and water from other contaminated regions. The application of microbial study in the aspects of heavy metal removal and purification of water with the adsorption technology has been focused. Thus, proving microbioremediation to be an effective field of research oriented towards heavy metal removal by microbes in the most effective, safe and economical way. Keywords: Bioremediation; biosorption; biosorbents; microbioremediation. 1. Introduction Heavy metals contamination has become a serious threat for the environmental safety, pressurizing soils, water streams, atmosphere and living systems. Generation of large quantities of toxic effluents containing metals, metalloids, lanthanides and radionuclides are deteriorating biodiversity, ecosystem and human safety. These anthropogenic interventions are consequences of industrial activities such as mining, smelting of iron ores, acid mine drainage, coal-based and nuclear power generation and electroplating industries (Volesky FB., 2007; Fomina M., and Gadd, GM., 1992). Heavy metal accumulation is deteriorating the ecosystem causing the problems of bioaccumulation and biomagnification. Furthermore, heavy metals can enter and disturb the ecosystem by the day to day practices also such as combustion of fossil fuels, use of disinfectants, fertilizers, batteries, and industrial activities (Colak et al, 2011). Some of them are useful to us at lower concentration but can be toxic at higher concentration. Metals such as Fe, Zn, Ca and Mg are biologically essential for mankind for growth and metabolic purposes. According to United States Environmental Protection Agency some heavy metals Cu, Ni, Cd, Zn, Cr, Se, Ag, Th, Be, As and Pb are the most hazardous heavy metals (Ghosh S., 2013). They are carcinogenic and toxic causing biomagnification in terrestrial and marine ecosystems (Janssen et al, 1993). It is a metabolically challenging task for living cells to retain suitable concentrations of Cu and Zn